Transiently controlled emission from ZnO surface
1Indian Institute of Technology Bhilai, Kutelabhata, Bhilai, Chhattisgarh 491002, India.
Nanotechnology
|July 19, 2024
Summary
Researchers controlled optical emission in zinc oxide (ZnO) using a photon excitation. A second light source at 402 nm reduced photoluminescence (PL) by 50%, offering defect control in ZnO materials.
Area of Science:
- Materials Science
- Solid State Physics
- Optoelectronics
Background:
- Zinc oxide (ZnO) exhibits significant photoluminescence (PL) due to defects.
- Below band gap excitation of ZnO reveals defect-related emission bands.
Purpose of the Study:
- To investigate photon-controlled optical emission in ZnO.
- To explore defect control mechanisms in ZnO using dual excitation sources.
Main Methods:
- Excitation of ZnO (101¯0) using 532 nm light to induce photoluminescence (PL).
- Application of a second excitation source at 402 nm to modulate PL.
- Analysis of PL spectra and Raman response.
Main Results:
- Observed significant PL overlapped with Raman response under 532 nm excitation.
- Identified three PL bands (629, 690, 751 nm) attributed to excess zinc and oxygen vacancies.
- Demonstrated a 50% reduction in overall PL by employing 402 nm excitation.
Conclusions:
- The doubly positive oxygen vacancy state in ZnO can be utilized to control PL emission.
- Transient reduction of oxygen vacancy density effectively modulates optical emission in ZnO.
